Conventionally, a virtual surround system, which improves the localization sensation of a sound image at a position deviated to the left or the right from the median plane of a listener, has been proposed (e.g., see Patent Document 1).
Further, conventionally, a technology, which stabilizes the localization sensation of a virtual speaker even in a case where the volume of one speaker is significantly smaller than the volume of the other speaker in a virtual surround system that improves the localization sensation of a sound image at a position deviated to the left or the right from the median plane of a listener, has been proposed (e.g., see Patent Document 2).